Distinguishing between boys and girls is now a violation of Title IX -- which was enacted to protect girls from discrimination.

On Tuesday, the Fourth Circuit Court ruled against a Virginia school district that sought to accommodate a transgender student while also protecting the privacy rights of other students.

The court concluded that Title IX of the Education Amendments of 1972--which prohibits discrimination on the basis of sex--should be interpreted as prohibiting discrimination on the basis of gender identity, as a Department of Education letter suggested in 2015. The ruling allows a lawsuit brought by a transgender student to proceed.

The case involves a biological girl who identifies as a boy. The court's majority explains it this way: "G.G.'s birth-assigned sex, or so-called 'biological sex,'" is female, but G.G.'s gender identity is male." Note the scare quotes around what the court calls "so-called ‘biological sex." Biological sex, in fact, is precisely what Congress protected in 1972.

The court's majority finds that to suggest that people with "different" gender identities do in fact have "different' gender identities marks them by their differences.

Nevertheless, G.G. sued the school district. Why? Because the district created a policy which says that bathroom and locker room access is primarily based on biology, while also creating accommodations for transgender students. Specifically, the policy is that only biological girls can use the girls' room, only biological boys can use the boys' room, and any student can use one of the three single-occupancy bathrooms, which the school created specifically to accommodate transgender students.